Characterization of the cellular microstructure of ocular lens using 2D power law analysis.

Power law analysis provides a quantitative method for characterization of spatial fluctuations in the cellular microstructure of the ocular lens. In the power law analysis, Fourier components of the spatial fluctuations are computed, and the relationship between the amplitude, A, and spatial frequency, f, of the components is defined by a power law function: [formula, see text]. The exponent of the function, beta, defines the scaling of the amplitude of the Fourier components as a function of spatial frequency. We performed two-dimensional power law analysis on electron micrographs of lens cells ranging from transparent to opaque. We identified two values of power law exponent, beta, for the spatial fluctuations of all lens cells, one for low- and a second for high-spatial frequencies. In the low-spatial frequency region, the value of beta was in the range of 0.53 to 1.33, for transparent and opaque cells. In the high-spatial frequency region, the value of beta increased from 2.78 for transparent lens cells to 3.60 for opaque lens cells. The power law analysis provides a new method for quantitative characterization of the spatial fluctuations in the microstructure of transparent and opaque lens cells.